Family Renillidae

Renilla reniformis (Pallas, 1766)

Pennatula reniformis Pallas, 1766:374.

Remarks. This species is easily recognizable as the only leaf-shaped octocorallian in the shallow South Atlantic Bight, and is well described by its familiar name, “sea pansy”. The frond (oozooid) is approximately as wide as it is long, with polyps (autozooids and siphonozooids) restricted to the upper surface. Sclerites are in the form of three flanged rods, which are longer in the frond than in the stalk. The color of the colonies includes varying shades of rose and purple.
Renilla reniformis is distinguishable from its southern tropical counterpart, R. mülleri, by the shape of the frond, which is not conspicuously wider than long, and by the sclerites of the stalk, which are shorter than those in the rachis. Both species can vary in intensity of color. Colonies can be found in intertidal systems and tidal creeks, as well as deeper marine habitats with soft sediment. The species is well known for its ability to bioluminesce.
There are numerous lots of this species in the NMNH from the shallow SAB.

Atlantic distribution: North Carolina to Brazil, Caribbean, 1-72 m (Deichmann, 1936; Bayer, 1961; NMNH collections; SERTC collection).

Figure 1. Renilla reniformis , live specimen (S427), whole colony (approximately 22 mm in diameter).

Figure 2. Renilla reniformis frond with expanded polyps.